    \begin{tikzpicture}
    %------------------------------------------------------------------------------------
    %    图片2.9
        \newcommand{\Yshift}{-2em}
	\newcommand{\Redcross}[1]{\textcolor{red}{\bcancel{\textcolor{black}{\mathrm{#1}}}}}
        \node (化简步骤) at (0,0) {化简步骤:};
        \node[shape=dart, draw, fill=gray!20, scale=0.5] at ([xshift=-3em]化简步骤) {};
        \node (1) at ([xshift=2em,yshift=\Yshift]化简步骤) {1.删除\quad$\mathrm{A \rightarrow A}$;};
        \node[anchor=west] (2) at ([yshift=\Yshift]1.west) {2.\ \textcolor{blue}{删除}\textcolor{red}{不终结}\textcolor{blue}{产生式:}};
        \node[anchor=west] (vt) at ([xshift=-1em,yshift=\Yshift]2.west) {$\mathrm{\because V_{VT}=\{A, D, G, B, S\} ;\quad\therefore}$ 应删除 $\mathrm{C,E}$ (连同其产生式)};
        \node[anchor=west] (得) at ([xshift=1em,yshift=\Yshift]vt.west) {得:};
        \node[anchor=west, align=left, draw, fill=yellow!20, rounded corners] (f1) at ([xshift=0.5em,yshift=-0.7em]得.east) {$\mathrm{G^{\prime}(S): S \rightarrow Be;\ \ A \rightarrow Ae \mid e;\ \ B\rightarrow Af; }$\\
            \qquad\quad\ $\Redcross{D\rightarrow f};\ \ \Redcross{G\rightarrow b};$};
        \node[anchor=west] (3) at ([yshift=-7.5em]2.west) {3.\ \textcolor{blue}{删除}\textcolor{red}{不可用}\textcolor{blue}{产生式:}};
        \node[anchor=west] (us) at ([yshift=-7.5em]vt.west) {$\mathrm{\because V_{US}=\{S, B, A\} ;\quad\therefore}$ 应删除 $\mathrm{D,G}$ (连同其产生式)};
        \node[anchor=west] (整理) at ([yshift=\Yshift]us.west) {※ 整理后得:$\mathrm{G^{\prime \prime}(S)}$:};
        \node[anchor=west, draw, align=center, fill=purple!20, rounded corners,minimum width=7em] (f2) at ([xshift=1em,yshift=-1.5em]整理.east) {
            $\mathrm{S\rightarrow Be}$\\
            $\mathrm{A\rightarrow Ae\mid e}$\\
            $\mathrm{B\rightarrow Af}$
        };
        \node[anchor=west, draw, align=left, fill=gray!20, rounded corners] (f3) at ([xshift=1em,yshift=4em]1.east) {
            $\mathrm{G(S):\ \ S\rightarrow Be\mid \Redcross{Ec}}$\\
            \qquad\quad\ \ $\mathrm{A\rightarrow Ae\mid e\mid \Redcross{A}}$\\
            \qquad\quad\ \ $\mathrm{B\rightarrow \Redcross{Ce}\mid Af}$\\
            \qquad\quad\ \ $\Redcross{C\rightarrow Cf}; D\rightarrow f; G\rightarrow b$
        };
        
        \draw [decorate, decoration=brace, thick, red] ([xshift=-7em]us.north east) -- ([xshift=-1em]us.north east);
        \node [shape=single arrow, draw=red, minimum height=3em, thick, single arrow tip angle=80, shape border rotate=90, scale=0.7] (arr1) at ([xshift=-4em,yshift=1.3em]us.north east) {};
        
        \draw [decorate, decoration=brace, thick, red] ([xshift=-7em]vt.north east) -- ([xshift=-1em]vt.north east);
        \node [shape=single arrow, draw=red, minimum height=5em, thick, single arrow tip angle=80, shape border rotate=90, scale=0.7] (arr2) at ([xshift=-4em,yshift=2em]vt.north east) {};
        
        %\draw [draw=red, -{Triangle[width = 1.2em, length = 1em]}, line width=0.4em] (1.east) -| ([xshift=6em,yshift=1.5em]1.east);
        \node [shape=single arrow, draw=red, minimum height=6em, thick, single arrow tip angle=80, shape border rotate=90, scale=0.7, rotate=290] (arr3) at ([xshift=2em,yshift=0.7em]1.east) {};

    \end{tikzpicture}